Bit block



June 30, 1936. LEE 2,046,026

BIT BLOCK Filed May 16, 1935 2 Sheets-Sheet l 11E II INVENTOR mlkja dam A M A. L. LEE

BIT BLOCK June 30, 1936.

Filed May 16, 1935 2 Sheets-Sheet 2 INVENTOR Patented June 30, :1936

UNITED 'STATES PATENT OFFICE m'r BLOCK Arthur L. Lee, Oakmont, Pa.

Application May 10, 1935, Serial No. 21,731

15 Claims. (01. 262-33) This invention relates to a bit block for mounting cutter bits .in a cutter chain for use in coal mining, and to a specialized assembly of the bit block in a bit-carrying link of a cutter chain.

As is well known, cutter chains are used in coal mining to cut a kerf in a seam of coal, so that when a charge of explosive is detonated in the coal the kerf which has been out in the seam permits the body or coal which has been shot to be more thoroughly shattered. In orderthat cutter chains may cut a kerf of adequate width, the cutter bits are, throughout the chain, arranged at varying angles, so that when observed appropriately in end elevation a fan-like arrangement of cutters, generally comprising five or more cutters, is to be seen.

Heretofore, it has been the practice initially to make the bit-carrying links of a cutter chain in forms appropriate to the angular positions of the cutter bits to be carried by the chain, in order that as made up the chain may present its fanlike spread of bits. Such practice increases manufacturing difllculty and expense, in that diflerent patterns, or dies, must be utilized for the different links adapted to carry cutter bits at the various angles requisite for kerf cutting. This is true, whether the bit-carrying links are integrally cast, or whether they are cast or forged sectionally and. thereafter welded, or otherwise interconnected.

One object of my invention is to provide a bit block for mounting on the lower sprocket-engaging body of bit-carrying links, and a cooperative arrangement of bit block and sprocket-engaging member, in which all the elements of each type, going to make up the several bit-carrying links as incorporated in a cutter chain, may be uniform in their structure, variation in the angularity of the cutter bits being obtained by varied mounting of the bit block elements on the sprocket-enga ing elements of the bit-carrying links.

Another object of the invention is to provide a bit block which may be economically manufactured, and which is of relatively great strength with respect to the weight of metal comprised the sprocket-engaging member of the assembly may be of standard form and dimensions, and in which the bit block is adapted to receive and engage a cutter bit of much less than standard thickness.

A still further object of my invention is so to provide means for mounting thin cutter bits on a sprocket-engaging member, or body, or standarddimensions, that an increased number 01' cutter bits may be included in each set, which defines the cutting spread, or arc, of the chain.

In the accompanying drawings Fig. I is a side elevation of a bit-carrying link of a cutter chain made in accordance with my invention, showing two connecting links associated with the bit-carrying link, and a sprocket associated with thelinks.

Fig. II shows in end elevation the bit-carrying link of Fig. I, the view being taken primarily on the section line IIlI of Fig. -I, but omitting, for the sake of clearness, sectional representation of the connecting link and sprocket which otherwise would appear in this figure.

Fig. 111 is a transverse, vertical section through the bit-carrying link of Fig. I, taken on the irregular section line III-III 01' Fig. I, and omitting the sprocket tooth intersected by the section line.

Fig. IV is an end elevation, similar to the showing of Fig. 11, but illustrating in full lines, and in dotted lines, an angular mounting of bit blocks on the body of a bit-carrying link.

Fig. V is a vertical, sectional view through the assembly of a bit block on the body of a bit-carrying link.

Fig. VI is an isometric view showing individually a bit block made in accordance with my invention.

Fig. VII is an exploded, isometric view, illustrating one mode 01' manufacturing the bit block.

Fig. VIII is also an exploded, isometric view, but illustrates another mode of manufacturing the bit block.

In the drawings reference numeral l designates generally the sprocket-engaging member, or body, of a bit-carrying link. This body memher comprises side members 2, which have outwardly projecting flanges, or gibs, adjacent their lower edges, and a bridging mass of metal 4, interconnecting the two side members, and overlying the sprocket tooth receiving space 5 between the side members. The upper surface of the bridging portion 4 of the link body curves downwardly in both lateral directions from the median, longitudinal, vertical plane of the body, so that the bridge I is of approximately semicylindrical form, as viewed from above. erally considered, the body I of the link may be integrally cast, may be forged and welded, or may be otherwise made up in any desirable manner. i

The bit hiock, designated generally by reference numeral 6, is a body, approximately eilipticai in cross section, which comprises two side members 'I aid 8 and an intermediately positioned backing member 9, for supporting the rearwardly presented face of a bit III. In the bit block, backing member 9 serves to interconeel; the two side members I and 8 in spaced relation with each other. As the backing member 9 covers a relatively small proportion of the interior surface area of each of the side members, the spacing of the side members provides an interval I I for the reception of a cutter bit, and clamping means for the cutter bit.

Referring to Figs. II and III of the drawings, the bit blocii is shown as positioned bodily on 'thebody member I of the connecting link, in

position to carry the cutter bit in alignment with a median, longitudinal, vertical plane of the body member. As shown, the bit block 6 is mounted on, and integrated with, body member I by two longitudinal extending welds I2 along the lower edges of the bit block. It will be observed that the transversely curved surface contour of bridge member 4, in cooperation with inwardly curved surfaces I3 at the lower edge of each of the side members of the bit block, provides in effect longitudinally extending grooves of such dimensions as to receive a substantial body of welding metal for integrating the bit block to the body member. As shown, the inwardly curved regions I3, adjacent the terminal edges of side members I and 8, are formed with the optimum curvature to provide adequate area of bonding surface for the weld, while forming with the curved surface I 4 of bridge member I, wedge-shaped intervals for reception of the welding metal.

Referring to Fig. IVof the drawings, the full line representation of the bit block shows the bit block mounted in welded union on the body member I, in position to extend angularly to the projected, median, longitudinal, vertical plane of the body member; and the dotted line representation of a bit block iilustrates a mounting of the bit block on the body member inclined to that plane, oppositely and unequally to the inclination of the bit block shown in full lines. The dotted line position may be taken as the extreme angular position in which the bit blocks are mounted on different body members; while the full line showing of the bit block may be taken to illustrate a position intermediate the extreme angular position, and the verticallyaligned position shown in-Figs. II and HI.

Fig. V of the drawings, showing the assembly of body member and bit block partly in iongitudinal, verticalsection, illustrates particularly the means for clamping the cutter bit in position. The bit I0 is shown as lying in the interval II bounded by the interiorly presented faces of the side members I and 8, and the forwardly presented edge of the backing member 8, and thus has fixed support on three sides. In this mounted position, with its lower edge resting upon the upper surface I4 of the bridge member 4 of the body member, pressure is exerted on the forward face of the bit- III to clamp it firmly in position by a bit clamp I5. Bit clamp I5 has a serrated edge It presented to the bit, and is Genin the form of a bridle of suitable dimensions to lie within the interval II between the side members of the bit block. Opening I6 to receive a rectangular nut I1 is provided in the hodyof the bit clamp, and the body of the bit clamp 5 surrounding this opening is made discontinuous toward the forward end of the bit block, to give access to a set-screw I8.

, As shown most clearly in Figs. VI to VIII inclusive of the drawings, the side members I and 8 have therethrough reotangular openings I9, with which the opening I 5 through the bit clamp may be brought into register, and have extending inwardly from their forward faces arcuate grooves 20 to accommodate the shank of bolt I8 in the interval between the side members.

When, therefore, the assembly, as shown in Fig. I and Fig. V, is made, rectangular nut I1 lies in the opening 6 of the bit clamp and in the openings I9 of the side members to which latter 20 openings itis approximately sized. The shank of set-screw I8 may then be introduced into the interval II between the side members, and into the bore of nut II, which lies in the opening I6 of the bit clamp, and the aligned openings I9 5 in the side members 1 and 8. Since rectangular nut I1 is unable to turn in the openings I9 of the side members in which it lies, the set-screw is given longitudinal travel by being turned in the nut, and may thus be caused to bear against the 30 felt clamp, inwardly of the nut II, to force the bit clamp against the opposed face of the bit II).

It will'be noted that no special means are provided for securing the bit clamp between the side members of the bit block. Any such meansare 35 unnecessary, since the assembly of nut I1 and set-screw I8, with the nut lying in the opening I6 through the bit clamp, as well as in the openings I9 of the side members, prevents displacement of the bit clamp. As shown in Fig. V, bit clamp I5, like bit III, rests upon the upper surface of bridge member s.

In its assembled condition, shown in Fig. VI, and in the preceding figures of the drawings, bit block 6 is an element of simple form, which may be made either as an integral casting, may be made up of forgings welded to each other, or may be made of welded stampings.

Fig. VII of the drawings shows one side member Ia of the hit block forged integrally with a backing member 9a for union with an opposite side member 8a. which may be either a forged or a stamped element. In integration of these elements, to provide the complete bit block, the inward surface of the side member 8a and the surface of the backing member 9a which is presented toward it, may be bonded, as by spot welding.

Fig. VIII shows, as initially individual eiements, side members 'Ib and 8b, and a backing member 60 5b. These separate elements may all be formed by a stamping operation, although they may, if desired, be forgings. In integration of these elements, to provide an integrated bit block, the union may be made by spot welding both the 5 side members lb and 8b to the backing member 9b. Desirably, in integrating the bit block from the parts, or elements, as shown in both Fig. VII and Fig. VIII, a weld is made along the rearward face of the bit biock, the more firmly to 7 bond the elements of the structure.

It will be noted that the elements of the bit block, and the manner in which they are welded to each other to form an integral bit block, correspond generaiiy to the form and welding of 75 elements to provide a bit-carrying link disclosed in my co-pending application Serial No. 733,370, filed July 2, 1934. Referring also to preceding figures of the drawings, it will be seen that the bit block of this invention is adapted to receive a thin cutter bit, of the type shown in that copending application. In that application, however, the entire bit-carrying link is constructed in conformity with the use of a thin cutter bit, received between the side members of the structure, and the entire bit-carrying link is, therefore, relatively thin and light, requiring a sprocket of special form in use of the chain. This invention, on the contrary, provides a bit block, made to receive and clamp a thin cutter bit which may be applied to a body member of standard dimensions, and adapted to be used with a usual form of sprocket. I

The use of thin cutter bits, in connections where they may advantageously be used, presents economy both in initial manufacture of the bits, and in their continued use, since thin cutter bits, such as the bit Ill herein shown, may be made from a simple rectangular bar, by shearing; forging, or a similar forming operation, is unnecessary in their manufacture. In use such cutter bits may be sharpened merely by grinding down their rearwardly inclining edges, without subjecting the bits to a reforging operation. Each cutter bit, being reversible, has two cutter points, and its useful life is increased by that fact also. The bit block of my invention, by conveniently adapting thin cutter bits to use with a sprocketreceiving member of standard dimensions, thus presents advantage additional to the primary advantage of making up cutting chains from elements which may be uniform throughout the chain. It will be apparent that the mounting of the cutter bit in the bit block is such as to avoid the necessity of machining operations to provide a bit-receiving recess and means for clamping the cutter bit into position.

As an additional advantage of the structure, it may be noted that the mounting of a bit block in selected angular position with respect to the arcuate face of a. body member for cooperating with the sprocket, and adapted for the mounting of thin cutter bits, permits an increased number of bits to be comprised within the kerf cutting spread, or arc, of a cutter chain, without overlapping the bodies of the cutter bits comprised in each set forming the cutting spread, or arc. This leads to eiiiciency in the cutting operation, as performed by the chain.

I claim as my invention:

1. A cutter chain comprising a, plurality of bitcarrying links having the bits thereof extending at different angles to a median plane to provide a kerf-cutting spread, said several bit-carrying links comprising identical body elements adapted to receive sprocket teeth and identical bit-holding elements, the said body elements having upwardly presented surfaces sloping downwardly to both sides of the median longitudinal vertical plane of the body element and the said several bit-holding elements being welded to the upwardly presented surfaces of the several body elements to lieat different angles to a common median plane, whereby in the cutter chain the bit-carrying links comprising identical parts provide variety in angularity for the mounting of bits adequate to form a kerf-cutting spread.

2. A bit-carrying link adapted for inclusion in a cutter chain comprising a body element adapted to receive a sprocket tooth and having an upwardly presented surface sloping downwardly to both sides of the median, longitudinal, vertical plane of the body element, and a. bit-holding element mountable in selected position on the upwardly presented surface of said body element.

3. A bit-carrying link adapted for inclusion in a cutter chain comprising a body element adapted to receive a sprocket tooth and having an exterior surface presented away from the sprocket tooth receiving region of the element which is curved transversely of the body element, and a. bit-holding element adapted to be mounted on the said surface oi the body element in selected position to lie at a selected angle to a vertical plane taken longitudinally through the said body element.

4. A cutter chain in accordance with the com- "bination of claim 1 in which the several identical bit-holding elements comprise each two side members spaced by a bit-backing member to define a narrow bit-receiving space therebetween,

and in which each bit-carrying link is integrated by a welded union between the said body elefilelig'lii and the said bit-holding element of the 5. A cutter chain in accordance with the combination of claim 1 in which the several identical bit-holding elements comprise each two side members spaced by a bit-backing member to de-' fine a narrow bit-receiving space therebetween, the said side members being initially separate and the structure of the element having welded integration in the region of the bit-backing member, and in which each bit-carrying link is integrated by a welded union between the said body element and the said bit-holding element of the link.

6. A bit-carrying link adapted for inclusion in a cutter chain comprising a body element adapted to receive a sprocket tooth and having an upwardly presented surface sloping downwardly to both sides of the median, longitudinal, vertical plane of the body element, and a bit-holding element mountable in selected position on the upwardly presented surface of said body element, said bit-holding element being a welded assembly comprising two side members providing space for the reception of a cutter bit therebetween and a. bit-backing member filling the space between the side members at one end of the bitholding element.

7. A bit-carrying link adapted for inclusion in a cutter chain comprising a body element adapted to receive a sprocket tooth and having an upwardly presented surface sloping downwardly to both sides of the median, longitudinal, vertical plane of the body element, and a bit-holding element mountable in selected position on the upwardly presented surface of said body element, said bit-holding element being a welded assembly comprising two side members providing space for the reception of a cutter bit therebetween and a bit-backing member filling the space between the side members at one end of the bitholding element, the welded connection between the members of the bit-holding element being in the region of the backing member and in assembly a bottom wall for the bit receiving space in the bit-holding element being provided by the adjacent mounting surface on the body element of the link.

8. A bit-carrying link adapted for inclusion in a cutter chain comprising a body element adapted to receive a sprocket tooth and having an upwardly presented surface sloping downwardly to both sides of the median, longitudinal, vertical plane of the body element, and a bit-holding element mountable in selected position on the upwardly presented surface of said body element, said bit-holding element comprising side members spaced from each other by a bit-backing member, and the under edges of the side members being beveled to provide between said edges and the sloping surface of the body element grooves to receive welding metal for welded integration of the two elements of the bit-carrying link.

9. A bit block formed as a separate element for exterior integration with a body element forming the sprocket-engaging portion in a bitcarrying link of a cutter chain, said bit block being a bit-holding element comprising two side members spaced by a bit-backing member to define a narrow bit-receiving space therebetween.

10. A bit block formed as a separate element for integration with a body element forming the sprocket-engaging portion in a bit-carrying link of a cutter chain, said bit block being a bit-holding element comprising two side members spaced by a bit-backing member to define a narrow bitreceiving space therebetween, the said side mem bers being initially separate and the structure of the element having welded integration in the region of the bit-backing member.

11. A bit block formed. as a separate element for integration with a body element forming the sprocket-engaging portion in the bit-carrying link of a cutter chain, said bit block being a bitholding element comprising two side members spaced by a bit-backing member to define a narrow bit-receiving space therebetween, said side members being recessed to provide a seat for a nut, a nut non-rotatably mounted in said seat cooperatively to engage a longitudinally extending set-screw, and a bit clamp formed to embrace said nut and to be thereby held in the assembly in a position of opposition to said bitbacking member and in position to be contacted inwardly of the assembly by the inwardly presented terminal of a set-screw cooperating with said nut.

12. A bit block formed as a separate element for integration with abody element forming the sprocket-engaging portion in a bit-carrying link of a cutter chain, said bit block being a bit-holding element comprising two side members spaced by a bit-backing member to define a narrow bitreceiving space therebetween, the said side members being initially separate and the structure of the element having welded integration in the region of the bit-backing member, said side members being recessed to provide a seat for a nut, a nut non-rotatably mounted in said seat cooperatively to engage a longitudinally extending set-screw, and a bit clamp formed to embrace said nut and to be thereby held in the assembly in a position of opposition to said bit-backing member and in position to be contacted inwardly of the assembly by the inwardly presented terminal oi the set-screw cooperating with said nut.

13. In a bit-carrying link a bit-holding structure comprising a body'having therein a bitreceiving recess terminating at one end thereof in a bit-backing surface, a longitudinally extending recess adapted to receive a set-screw and communicating with said bit-receiving recess, a nutreceiving recess extending laterally from. said setscrew recess, a nut in said lateral recess and mounted against rotation therein, a set-screw threaded in said nut for linear movement longitudinally of the bit-holding structure, and a bitclamping member formed to embrace said nut and to be thereby held in a position of opposition to said bit-backing surface and in position to be contacted inwardly of the assembly by the inwardly presented terminal of the set-screw cooperating with said nut.

14. In a bit-carrying link a bit-holding structure comprising a body having therein a bitreceiving recess terminating at one end thereof in a bit-backing surface, a longitudinally extending recess adapted to receive a set-screw, a nut mounted against rotation with its threaded bore in alignment with the set-screw receiving recess of the bit-holding structure. a. set-screw threaded in said nut for linear movement longitudinally of the bit-holding structure, and a bit clamp formed to embrace said nut and to be thereby held in a position of opposition to said bit-backing surface and in position to be contacted inwardly of the assembly by the inwardly presented terminal of the set-screw cooperating with said nut.

15. In a bit-carrying link a bit-holding structure comprising a bodyhaving therein a bitreceiving recess terminating at one end thereof in a bit-backing surface, a longitudinally extending recess adapted to receive a set-screw, a. nutreceivlng recess extending laterally from said set-screw recess, a nut in said lateral recess, said nut and recess being relatively so shaped as to prevent rotation of the nut as mounted in the recess, a set-screw threaded in said nut for linear movement longitudinally of the bit-holding. structure, and a bit-clamping member formed to embrace said nut and to be thereby held in a position of opposition to said bit-backing surface and in position to be contacted inwardly of the assembly by the inwardly presented terminal of the set-screw cooperating with said nut.

ARTHUR L. LEE. 

